Field of the Invention
The present invention relates to a polarizing plate and a method for manufacturing the polarizing plate.
Description of the Related Art
As a polarizing plate used for a liquid crystal display device or the like, a polarizer including protective films bonded to both surfaces thereof is generally used. Examples of the polarizer include a polarizer obtained by adsorbing a dichroic material such as iodine or a dichroic dye to a polyvinyl alcohol-based film and further orienting the film by stretching. From the viewpoint of a decrease in the thickness of the polarizing plate and a reduction in the number of members, or the like, a technique of bonding a retardation film containing a thermoplastic norbornene-based resin in place of one protective film has been proposed (see Patent Document 1).
The liquid crystal display device is often used for a long period of time wider a high temperature condition or the like because of the wide usage of the liquid crystal display device. For example, the liquid crystal display device is often used for vehicle installation and a handheld terminal. As a result, the polarizing plate is also required to have reliability (durability) such that the polarizing plate suffers from no deterioration in optical property when the polarizing plate is placed under a high temperature condition or high temperature/high humidity conditions.
However, since the triacetyl cellulose film used for the protective film is water-vapor permeable (has a high water-vapor permeability), the optical property of the polarizer and the adhesion property of an adhesive are deteriorated by the absorption of moisture, which may cause display unevenness. On the other hand, there has been proposed a technique of providing at least one resin layer between the polarizer and the protective film in the polarizing plate or on the surface of the polarizing plate to reduce a dimensional change rate under a heating humidification condition, thereby improving durability (Patent Document 2).